Interaction between organic molecules and a gold nanoparticle: a quantum chemical topological analysis

2021 ◽  
Vol 140 (8) ◽  
Author(s):  
Rika Tandiana ◽  
Nguyen-Thi Van-Oanh ◽  
Carine Clavaguéra
Keyword(s):  
Gold Nanoparticle ◽  
Quantum Chemical ◽  
Organic Molecules ◽  
Topological Analysis

scholarly journals Real-time prediction of 1H and 13C chemical shifts with DFT accuracy using a 3D graph neural network

2021 ◽  
Author(s):  
Yanfei Guan ◽  
S. V. Shree Sowndarya ◽  
Liliana C. Gallegos ◽  
Peter C. St. John ◽  
Robert S. Paton
Keyword(s):  
Neural Network ◽  
Real Time ◽  
Quantum Chemical ◽  
Organic Molecules ◽  
Chemical Shifts ◽  
13C Chemical Shifts ◽  
Time Prediction ◽  
Nmr Data ◽  
Proton Chemical Shifts

From quantum chemical and experimental NMR data, a 3D graph neural network, CASCADE, has been developed to predict carbon and proton chemical shifts. Stereoisomers and conformers of organic molecules can be correctly distinguished.

Synthesis and Characterization of Super-Molecular Ionic Liquids

2011 ◽  
Vol 197-198 ◽  
pp. 906-910
Author(s):  
Hui Ru Liu ◽  
Li Qiang Lv ◽  
Xing Chen Zhang
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Melting Point ◽  
Quantum Chemical ◽  
Organic Molecules ◽  
Raw Materials ◽  
Ammonium Thiocyanate ◽  
Molar Ratio ◽  
Molecular Ion

This study concerned a novel super-molecular ionic liquid synthesized by ammonium thiocyanate and caprolactam. The physical characters such as melting point and electric conductivity were investigated. Results showed that the melting point is -12.2°C at the molar ratio of 3:1 (caprolactam/ammonium thiocyanate), which is much lower than raw materials. The electric conductivities of synthesized ionic liquids were close to that of imidazole ILs. The structure of ionic liquid was characterized by IR,1HNMR and quantum chemical calculations. It was shown that the NH4+cation connected with caprolactam organic molecules by hydrogen bonds, leading to the forming of a super-molecular ion. The electrostatic attraction of super-molecular ion with anion was decreased because of the larger volume of super-molecular ion than original cation, thus the melting point decreased. The key properties that distinguish super-molecular ionic liquid from other ILs were the presence of supermolecular ion, which can be used to build up a hydrogen-bonded network. This type ion liquid was named as super-molecular ion liquid.

scholarly journals Quantum Chemistry Meets Machine Learning

2019 ◽  
Vol 73 (12) ◽  
pp. 983-989 ◽  
Author(s):  
Alberto Fabrizio ◽  
Benjamin Meyer ◽  
Raimon Fabregat ◽  
Clemence Corminboeuf
Keyword(s):  
Machine Learning ◽  
Statistical Learning ◽  
Quantum Chemical ◽  
Large Scale ◽  
Organic Molecules ◽  
Chemical Properties ◽  
Learning Approaches ◽  
Energy Landscapes ◽  
Free Energy Landscapes ◽  
Large Scale Screening

In this account, we demonstrate how statistical learning approaches can be leveraged across a range of different quantum chemical areas to transform the scaling, nature, and complexity of the problems that we are tackling. Selected examples illustrate the power brought by kernel-based approaches in the large-scale screening of homogeneous catalysis, the prediction of fundamental quantum chemical properties and the free-energy landscapes of flexible organic molecules. While certainly non-exhaustive, these examples provide an intriguing glimpse into our own research efforts.

Validation of the mPW1PW Quantum chemical calculations for the vibrational study of organic molecules - re-assignment of the isopropylamine vibrational spectra

2011 ◽  
Vol 24 (2) ◽  
pp. 110-121 ◽  
Author(s):  
Sara Padrão ◽  
Sónia M. Fiuza ◽  
Ana M. Amado ◽  
António M. Amorim da Costa ◽  
Luis A. E. Batista de Carvalho
Keyword(s):  
Quantum Chemical Calculations ◽  
Vibrational Spectra ◽  
Quantum Chemical ◽  
Organic Molecules ◽  
Vibrational Study

Bonding between nonbonded sulfur and oxygen atoms in selected organic molecules (a quantum chemical study)

1987 ◽  
Vol 109 (8) ◽  
pp. 2237-2245 ◽  
Author(s):  
Janos G. Angyan ◽  
Raymond A. Poirier ◽  
Arpad Kucsman ◽  
Imre G. Csizmadia
Keyword(s):  
Quantum Chemical ◽  
Organic Molecules ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Oxygen Atoms

scholarly journals Charge Density Analysis and Transport Properties of TTF Based Molecular Nanowires: A DFT Approach

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Karuppannan Selvaraju ◽  
Poomani Kumaradhas
Keyword(s):  
Density Distribution ◽  
Charge Density ◽  
Electron Density ◽  
Quantum Chemical ◽  
Molecular Conformation ◽  
Topological Analysis ◽  
Basis Set ◽  
Bond Critical Point ◽  
Chemical Calculation ◽  
Energy Density Distribution

The present study has been performed to understand the charge density distribution and the electrical characteristics of Au and thiol substituted tetrathiafulvalene (TTF) based molecular nanowire. A quantum chemical calculation has been carried out using DFT method (B3LYP) with the LANL2DZ basis set under various applied electric fields (EFs). The bond topological analysis characterizes the terminal Au–S and S–C bonds as well as all the bonds of central TTF unit of the molecule. The variation of electron density and Laplacian of electron density at the bond critical point of bonds for zero and different applied fields reveal the electron density distribution of the molecule. The molecular conformation, the variation of atomic charges and energy density distribution of the molecule have been analyzed for the various levels of applied EFs. The HOMO-LUMO gap calculated from quantum chemical calculations has been compared with the value calculated from the density of states. The variation of dipole moment due to the polarization effect and the I-V characteristics of the molecule for the various applied EFs have been well discussed.

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